Commercial cooking ovens (e.g., such as rack ovens) commonly burn gaseous fuel and pass the combustion exhaust gases through heat exchange tubes of a heat exchanger and then up a stack and through an exhaust system to be delivered external to the oven. Cooking air is recirculated from the cooking chamber past the heat exchange tubes to pick-up heat, and the heated cooking air is then delivered back to the cooking chamber. Some level of efficiency is generally lost in the heat exchange between the combustion gases and the cooking air.
It would be desirable to provide an oven that makes direct use of the combustion exhaust gases so as to reduce the wasted heat and energy during oven operation.